Changes between Version 63 and Version 64 of io_operations

Timestamp:

Jan 24, 2020, 1:09:43 PM (4 years ago)

Author:

alain

Comment:

--

io_operations

@@ -142 +142 @@
 '''1)''' The TXT[0] terminal is reserved for the kernel. It is normally used by the kernel to display log and/or debug messages. It can also be used by user processes for debug, through the specific display_xxx() system calls, that should not be used in normal exploitation.
 
-'''2)''' The other (NB_TXT_CHANNELS - 1) terminals TXT[i] are used by user processes. The first INIT user process,  creates  (NB_TXT_CHANNELS -1) KSH user processes (one shell per user text terminal). All processes created by a KSH[i] process share the same TXT[i] terminal as the parent process, and belong to the same group of process. 
+'''2)''' The other (NB_TXT_CHANNELS - 1) terminals TXT[i] are used by user processes. The first INIT user process,  creates  (NB_TXT_CHANNELS -1) KSH user processes (one shell per user text terminal). All processes created by a KSH[i] process share the same TXT[i] terminal as the parent process, and belong to the same "group" of processes. 
 
-'''3)''' The INIT process is never deleted : it does not call the exit() syscall, and cannot be killed. The the KSH[i] processes should not be deleted : the KSH main thread does not call the exit() sys call. But the KSH process can be killed, and is - in principle - automatically recreated by the parent INIT process, when it is killed.
+'''3)''' The INIT process is never deleted : it does not call the exit() syscall, and cannot be killed. The the KSH[i] processes should not be deleted : the KSH main thread does not call the exit() sys call. If the KSH process is accidentally killed, it is - in principle - automatically re-created by the parent INIT process.
 
 '''4)''' Regarding the WRITE accesses, all processes attached to the same TXT_TX[i] terminal can atomically display character strings. There is no guaranty on the order, when these strings are issued by different processes, because these strings are simply sequentialized by the server thread associated to the shared TXT_TX[i] device.